/*
 * XXX ab@apache.org: This class is copied verbatim from Xalan-J 2.6.0
 * XXX distribution, org.apache.xml.utils.XMLCharacterRecognizer,
 * XXX in order to avoid dependency on Xalan.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: XMLCharacterRecognizer.java 823614 2009-10-09 17:02:32Z ab $
 */
package ai.platon.pulsar.parse.tika

/**
 * Class used to verify whether the specified <var>ch</var> conforms to the XML
 * 1.0 definition of whitespace.
 */
internal object XMLCharacterRecognizer {
    /**
     * Returns whether the specified <var>ch</var> conforms to the XML 1.0
     * definition of whitespace. Refer to <A href="http://www.w3.org/TR/1998/REC-xml-19980210#NT-S"> the definition of
     * <CODE>S</CODE></A> for details.
     *
     * @param ch Character to check as XML whitespace.
     * @return =true if <var>ch</var> is XML whitespace; otherwise =false.
     */
    fun isWhiteSpace(ch: Char): Boolean {
        return ch.toInt() == 0x20 || ch.toInt() == 0x09 || ch.toInt() == 0xD || ch.toInt() == 0xA
    }

    /**
     * Tell if the string is whitespace.
     *
     * @param ch     Character array to check as XML whitespace.
     * @param start  Start index of characters in the array
     * @param length Number of characters in the array
     * @return True if the characters in the array are XML whitespace; otherwise,
     * false.
     */
    fun isWhiteSpace(ch: CharArray, start: Int, length: Int): Boolean {
        val end = start + length
        for (s in start until end) {
            if (!isWhiteSpace(ch[s])) return false
        }
        return true
    }

    /**
     * Tell if the string is whitespace.
     *
     * @param buf StringBuffer to check as XML whitespace.
     * @return True if characters in buffer are XML whitespace, false otherwise
     */
    fun isWhiteSpace(buf: StringBuffer): Boolean {
        val n = buf.length
        for (i in 0 until n) {
            if (!isWhiteSpace(buf[i])) return false
        }
        return true
    }

    /**
     * Tell if the string is whitespace.
     *
     * @param s String to check as XML whitespace.
     * @return True if characters in buffer are XML whitespace, false otherwise
     */
    fun isWhiteSpace(s: String?): Boolean {
        if (null != s) {
            val n = s.length
            for (i in 0 until n) {
                if (!isWhiteSpace(s[i])) return false
            }
        }
        return true
    }
}